Rules of the road: Carpool lane hours

FREEWAYS: 5-9 a.m. and 3-7 p.m. on most Bay Area freeways. Until 10 a.m. on ramp from south I-880 to west 237. And from 5 a.m. to 8 p.m. weekdays on south I-680 through Fremont.

AT FREEWAY-TO-FREEWAY RAMPS: Usually same hours as on freeways. Hours will be posted on black-and-white signs.

EXPRESSWAYS IN SANTA CLARA COUNTY: 6-9 a.m. and 3-7 p.m.

AT RAMPS FROM CITY STREETS: When no hours are listed, these carpool lanes are reserved 24 hours a day, seven days a week for carpoolers, motorcyclists or those with green or white stickers on their vehicles.